Tow blooming



June 7, 1966 J. K. PANNILL, JR. ETAL 3,

TOW BLOOMING Filed Oct. 10, 1963 O 2 Sheets-Sheet 1 row VSTEEL ROLL C DRIVEN RUBBER ROL L 5 H OE FLUTED ROLL MOTOR OR OTHER MEANS FOR ROTATING FLUTED ROLL JAMES K. PA/V/V/LL PAUL GALLAGER INVENTOR.

BY QMM ATTORNEYS June 7, 1966 J. K. PANNILL, JR.. ETAL 3,

TOW BLOOMING 2 Sheets-Sheet 2 Filed OJL 10, 1963 JAMES K. PAN/V/LL $2M m. 295.8% .35 mm $5888 q iviumz PAUL GALLAGHER 3,254,373 TOW BLOOMING James K. Pannill, Jr., and Paul Gallagher, Kingsport,

Tenn., assignors to Eastman Kodak Company, Rochester, NY, a corporation of New Jersey Filed Oct. 10, 1963, Ser. No. 315,265 3 Claims. (Cl. 19-65) This invention relates to blooming tow. More particularly it relates to method and apparatus for opening or blooming tow useful in the production of rod-like elements adapted for production of tobacco smoke filters and the like.

It has become well established in the man-made fiber industry, for example, as shown by US. Patents 2,794,- 239, 2,900,988 and 2,953,838 to our coworkers Crawford and Stevens, that some sort of opening or blooming treatment for crimped continuous filament tow is desirable, especially for tow to be compacted into rodshaped elements useful as tobacco smoke filters. One way of effectively accomplishing such blooming is by use of a gas-jet treatment such as taught by inventor Gallagher and his coworker Dyer in US. Patent 3,081,- 951. While such a method has proved highly acceptable 'in the industry, some manufacturers would prefer, if

available, an equally effective mechanical method of blooming tow which would also require no gas consumption. After extended investigation we have found just such a mechanical method and apparatus for opening continuous filament tow.

One object of this invention is to provide a method and apparatus for mechanically blooming continuous filament tow. Another object is to provide mechanical means for opening man-made continuous mul-tifilaments to adapt them for manufacture into rod-like elements such as tobacco smoke filters and the like. Further objects will be apparent hereinafter.

In' its broader aspects our invention involves a method and apparatus for blooming crimped continuous filament tow by passing the tow under tension between the bite of a spring-type gate or shoe and a fluted roll, preferably of rubber or similar type composition, which rotates at a speed faster than the rate of movement of the tow. Before passing between this bite the tow may be passed through the bite of two feed rolls, preferably one of which is a metal or alloy roll, e.g., steel, and the other a rubber roll. The gate or shoe consists of one or more pieces of spring steel or other flexible strip material such as piano wire assembled side by side in a parallel manner. The fluted roll is a dirven roll, and the flutes are preferably rounded or substantially U- shaped notches at a slight angle to the diameter. We have found a 30 notch highly effective. After passing United States Patent 2. e.g., as by handing, prior to being formed into filter rods or the like.

For a further understanding of our invention reference is made to the attached drawing which forms a part hereof.

In the drawing:

FIG. 1 is a perspective view of the shoe-roll blooming arrangement of this invention, including feed rolls.

FIG. 2 is a graph plotting weight against rod pressure for 2'samples of cellulose acetate tow treated according to this invention as compared to the same tow treated by gas-blooming. The weight-pressure drop relationship for the shoe-roll formed filament rods of this invention is seen to compare favorably to that already found acceptable to the industry for rods made of gas-bloomed filaments.

With reference to FIG. 1, continuous filament tow 10 is fed through the bite formed between roll 12, which may be of steel, and driven roll 14, preferably of rubber, rotating in opposite directions. The band of tow 16 is next carried through the bite for-med by a spring-shoe arrangement comprising one or more metal or appropriate alloy flexible sections or wires 18 arranged in parallel and the driven roll 20. The bloomed tow 22 is shown passing in the direction of further treatment after passing between the bite formed by shoe 18 and driven roll 20.

The spring shoe 18 may be of several types. For example, a single piece of spring steel 3 /2" by 8" with a thickness of 0.033" and 0.020" may be used. In another embodiment the shoe may be piano wires, e.g., 3 /2" long and A in diameter assembled side by side to make a shoe 8" or so wide. A further type of shoe may be made by using strips of spring steel A" by 3 /2" by .032" assembled side by side. The end of the shoe is depressed against the driven roll 20 driven by driving means 24 to a degree of force sutficient to bloom or open the tow 16. Roll 20 is preferably fluted and made of rubber. The flutes may be of a U-shaped, and we have found that 60 flutes equally spaced around the circumference of a roll of a diameter of about 10" give excellent results with respect to eflicient blooming of the tow. The flutes may be of a depth of about A" and slanted at an angle of about 30 degrees.

The tow 16 passing along in the interval between feed rolls 12 and 14 and treating shoe 18 and fluted roll 20 is under a tension. This tension may be effectively controlled by operating roll 20 approximately 3 times faster than the surface speed of driven roll 14.

The following example is illustrative of our invention.

Several different embodiments of the spring shoe-fluted roll blooming device of this invention were used to open crimped continuous cellulose acetate tows of various denier per filament and total denier. The results of through the shoe-roll bit the tow may be further treated this-treatment are recorded in the following table.

' Table Sample No 1 2 3 4 Denier (DF/TD in 1000s) Gm Tow 1 Rod .878 Red Pressure Percent Plastic 2 Hr. Hardness Roll Ratio Bloom Rating Shoe Type ber Roll. ber Roll.

From the foregoing description and example it is thought apparent that we have provided a novel and highly 'efi'icient mechanical method and apparatus for blooming continuous filament tow adapted for use in rodlike elements such as those used in cigarette filters by treating the tow with a spring shoe, the end of which is depressed against a driven roll, preferably fluted and made of rubber.

While in the above description we have referred to a rubber covered roll, such embraces either natural or synthetic rubbers. Also plastic compositions such as polyesters, polyolefins, polyarnides, polyurethanes and the like may be used for this roll surface.

Some of the other changes which may be made in our apparatus and method include the use of the driven roll, equipped with a shoe as described above, preceded by a pair of rolls retarded b y hydraulic or mechanical means. The tow passing through the nip of the pair of retarded rolls may thus be variably and randomly tensioned, depending upon its extensibility and upon the portion of the filaments held firmly between the driven roll and the bearing members of the shoe. The use of this technique to intermittently and randomly tension the tow tends to distribute the filaments more uniformly in the resultant bloomed tow.

Although the invention has been described in considerable detail with the reference to certain preferred embodiments thereof, variations and modifications can be effected within the spirit and scope of the invention as described hereinabove and as defined in the appended claims.

We claim:

1. Apparatus for blooming moving continuous filament tow comprising a rotatable roll adapted to be rotated in the direction of movement of said tow, a shoe, at least one strip of stationary flexible fingers held in said shoe positioned directly in contact with said rotatable roll, means for rotating said roll, means for moving tow between said strip and the moving surface of said roll whereby tow moving between said strip and said roll may be bloomed.

2. The apparatus according to claim 1 wherein the said strip comprises a plurality of parallel fingers of spring steel and said roll contains substantially evenly spaced around the circumferential surface thereof a plurality of flutes of a U-shape.

3. The apparatus according to claim 1 wherein the rol is constructed of rubber-like material.

References Cited by the Examiner UNITED STATES PATENTS 2,822,582 2/1958 Hayward et a1. 19-65 2,838,804 6/1958 Boer 19-65 2,858,574 11/1958 Boer 19-65 X 2,925,628 2/1960 Boer 19-258 2,930,270 3/1960 Brey 226195 X 2,978,752 4/1961 Cloutier et a1. 1965 3,032,829 5/1962 Mahoney et al 19-65 3,111,285 11/1963 Cocker et al. 226-495 X 3,156,016 11/1964 Dunlap et a1 1965 X DONALD W. PARKER, Primary Examiner.

J; PETRAKES, Assistant Examiner. 

1. APPARATUS FOR BLOOMING MOVING CONTINUOUS FILAMENT TOW COMPRISING A ROTATABLE ROLL ADAPTED TO BE ROTATED IN THE DIRECTION OF MOVEMENT OF SAID TOW, A SHOE, AT LEAST ONE STRIP OF STATIONARY FLEXIBLE FINGERS HELD IN SAID SHOE POSITION DIRECTLY IN CONTACT WITH SAID ROTATABLE ROLL, MEANS FOR ROTATING SAID ROLL, MEANS FOR MOVING TOW BETWEEN SAID STRIP AND THE MOVING SURFACE OF SAID ROLL WHEREBY TOW MOVING BETWEEN SAID STRIP AND SAID ROLL MAY BE BLOOMED. 